Light fixtures soften and spread the light from light bulbs to illuminate the entire room, but they are also magnets for dust, bugs, cobwebs, and dirt. Dirty light fixtures can also lessen the amount of light a room receives while using the same amount of energy and lower the lifespan of light bulbs.
Dangers of Cleaning Light Fixtures
One of the hardest parts of cleaning light fixtures is that it frequently requires a ladder. Add to that the fact that you are usually unscrewing the light fixture while on the ladder, and an accident is a possibility. It is possible to clean some light fixtures while in place, but that won't substitute for taking light fixtures down at least twice a year to give them a deep cleaning.
Another danger is that light bulbs get hot when they are on. To reduce the risk of burning, leave the light off for at least an hour before starting to clean fixtures. Another risk is because of electricity. I like to remove light fixtures from their electrical parts to clean and wash them. If you clean in place, you should use a dry dusting tool. If you need to wipe them down with a wet cloth, make sure the cloth is damp and not dripping. Dripping water or sprayed cleaning fluid can get into the electrical parts of your lighting and damage them or cause a risk of electrocution.
Weekly, light fixtures should be thoroughly dusted. This can be done with the light fixtures still in place. Use a long-handled dusting tool to reach and dust ceiling fixtures, chandelier pieces, and even recessed lighting. If this is done weekly, the deep cleaning portion of cleaning light fixtures should only need to be done twice a year.
Glass Ceiling Fixtures
Unscrew the light fixtures from the ceiling, lamp, or base. The first step will be to dump the dust, bugs, and any other dirt out of the light fixture into the trash. Next, I like to dust the inside and outside with a microfiber cloth or another duster. Sometimes this is all that is needed. But twice a year, at least, the fixtures will need to be washed. A sink with warm water and a few drops of mild dish soap is all that is usually needed to clean glass light fixtures. Allow them to soak for a few minutes before wiping them down and rinsing. Use a dry towel to wipe them completely dry, especially the inside. Now they are ready to replace. Never put glass light fixtures in the dishwasher. You run the risk of breaking them. Glass cleaner can also be used to spot clean glass light fixtures.
Depending on how elaborate your chandelier is, you may be able to dust in place for regular maintenance, but chances are a biannual cleaning will be needed where the chandelier needs to be taken down. I recommend photographing how the chandelier is put together to make reassembly a more simple process. You can mix your own cleaner in a spray bottle. Try a 1/4 cup of vinegar and 3-4 cups of water. Or you can add a few drops of dish soap to a spray bottle of water. Spray the crystals and pieces of the chandelier one section at a time. Drying right away with a microfiber cloth which will also help polish them. Reassemble the chandelier and see how it shines.
Recessed lighting can be cleaned most easily with regular dusting inside the opening after the light has been turned off for at least an hour. For deeper cleaning, carefully remove the bulb, and using a damp cloth, wipe the interior of the recessed area. To be extra careful, turn off the electricity for that part of the house as you work. Wipe down the bulb and replace it. Turn on the electricity and you have a cleaned light.